Material handling vehicles commonly include a material container for holding refuse, trash, or an aggregate material. Typically, the material container is substantially rectangularly configured and includes a closed front end and open rear end and tailgate through which material in the container can be discharged therethrough. The container usually is mounted to a vehicle frame, and depending on the type of material handling vehicle desired, each mounting system varies. For example, some material containers are pivotably mounted to the vehicle frame, such as a dump truck, to facilitate ready withdrawal of the contents in the container by allowing the contents to slide outwardly through the open rear end when the material container is pivoted and the front end is raised. Other material containers are fixed relative to the frame such as some commercially available trash compactors.
Additionally, the construction of the tailgate varies to suit the function of the vehicle. For example, many commercially available dump trucks have a tailgate which pivots outwardly to facilitate dumping when the material container front end is raised. U.S. Pat. No. 4,067,466 to Parks et al discloses another pivoting tailgate positioned on the material container of a refuse compactor. The material container is fixedly mounted to the truck frame and the coordinated movement of a compaction and discharge blade provides refuse compaction and then discharge. The tailgate includes a vertically raisable top section having a lower section pivotably connected thereto. As the upper section is raised, the lower section is free to pivot outwardly, thus providing a full discharge path for the compacted refuse. In another refuse compactor disclosed in U.S. Pat. No. 3,966,096 to Worthington, the material container is adapted for use on small trucks. The tailgate is designed to prevent a quick, uncontrolled discharge or dumping so that refuse material can be controllably metered into a much larger conventional refuse vehicle. The container rear end and the tailgate both are vertically and selectively movable. The tailgate does not pivot and the amount of discharged refuse is controlled by the selected size of the rear opening. Similar designs are used on trucks adapted to meter sand, salt or other aggregate material on a roadway.
One drawback of the aforementioned prior art material handling vehicles is their limited function. Each vehicle is constructed to provide only one means of discharge, i.e. either a controlled metering of discharged refuse or other aggregate material contained within the material container, or a less controlled, quicker discharge of material which is facilitated by an outwardly pivoting tailgate, such as a dump truck. It has been determined that a more general material handling vehicle is desirable which is constructed so that the material container and tailgate can provide not only a controlled metering of material therefrom, but also provide a less controlled, quicker discharge of material when needed.
With the foregoing in mind, it is therefore an object of the present invention to provide a material handling vehicle which overcomes the aforementioned deficiencies of the prior art.
It is another object of the present invention to provide a material handling vehicle which includes a pivotably mounted material container having a tailgate sized to close the open rear end of the container and where the tailgate can be selective moved between a closed position, a partially raised position so as to permit metering of material therethrough, and a fully raised position where the tailgate is free to swing outwardly to facilitate complete discharge of material.